Sorry to hear of your injury. We're here for you.
I was assaulted in a similar way on June 23, 2000. I got whiplash and a concussion. My wife says my personality changed.
There are a few things you need to look out for. Is you neck/upper neck still symptomatic? You may need to find an Upper Cervical Chiropractor to check this out. NUCCA.org has a referral list.
How are you sleeping? Do you dream and wake up refreshed? If not, your sleep needs to improve. My neck is still a problem if I sleep with it in a bad position.
Of course, you have learned the hard way about alcohol. No more than one serving ( a beer, glass of wine, no hard liquor) per sitting. Try to limit your caffeine to one cup per day.
I swear by vitamins and other supplements to help my brain work at its best. B-6, B-12, folic acid, all of the anti-oxidants, Omega 3's, Vit D3, etc. I and others have many posts about nutrition. Do a search. The injured brain needs extra levels of these supplements, first to overcome existing deficiencies, then to heal.
The road is long and slow for some of us. Get to know the new you, at least for the present. Work with your recovering brain, not against it. Slow down in your study intensity. take breaks from the books frequently. Avoid pushing it when you feel foggy brained.
Focus on lowering your stress load. The injured brain does not heal when under stress. It needs good REM sleep and lots of it.
I hope this helps. It is easy to get over-whelmed with a concussion that persists.
My best to you.